I also ran this one by my daughter who is just four years old. I assume most any girl will prefer a female Wizard over a male one, so I instead set it alongside the original Don Kueker female Wizard. I asked which one she liked more. Her answer was the princess. I got her to indicate the pricess was in fact the Kueker Wizard. I then asked her why she didn't choose Kristina's Wizard. Her answer was she looked like a baby. That is too young. The other Heroes appear in their twenties or thirties.
It's evident your going for a cohesive look with the four Heroes, where the hands, feet, and head are easier to view from the table. This works with the stockier males, yet my daughter's assessment indicates certain features are overlarge to be considered beautiful. I'd narrow the nose, jaw and cheeks, bring the eyes closer together, and reduce the lower lip a bit. Narrowing her hair at the top of her head should also mature her look, as would raising the bangs by returning her slim diadem. The Ebberon goggles only serve as a distraction.
The bottom of her legs and shoes also appear too big. The female Elf's feet may be too tiny to keep with the Heroes' look, but a thick-footed female breaks the smaller-female proportion. I think the female Elf's proportions would work better as a guide for a human female's head, while I'd go for something between the male and female Elf for the feet.
One reason I believe she identified the Kueker Wizard with a princess is the dress and cape. My guess is Kueker originally designed them down to the feet, like Sinestra the Archmage from the EQP. This doesn't connote the active nature of a dungeon-exploring Hero, but it does reflect her poor combat ability and superior range attack, combined with her outstretched arm. I like the Orc Shaman's robe length best as it reaches to his feet, though the Necromancer's robe length seems acceptable. Having it one, long robe, rather than a skirt and shirt piece helps sustain the impression of ranged spellcaster. I think this is more important than representing a more active and utilitarian look for combat and trap jumping. Another possible variant on the long dress could be it is split towards the bottom. This is partially suggested by some of the fold lines of the Kueker Wizard.
Sheathe the dagger, I say. She can't fight with it in her left hand, anyway. I'd also turn her body stance a bit, with her right foot more forward. Some of the Wizards of Morcar have a foot forward, and having her arm more out to the side will match not only the Wizards of Morcar stance, but it will reflect the Hero stance better, as well.
As for the Pamela Anderson boob-job, she's supposed to be a Wizard, not a bar wench. I do like how you cleverly converted the cape lapels, however.
Not sure if the gloves are necessary. I get a night-club performer/stripper vibe from them. Bracelets are better. She also could benefit from one or two of the Kueker beaded accessories to show off her female attitude toward magic.
I hope a criticism or two will be useful to you. My intent is to keep the female Wizard within both the parameters of HQ Hero design and the concept art. Of course, these are all just opinions. Weighed with the opinions of other members, I imagine you can retain the broadest market for the project.